Delivering water in the Murray system has always been challenging due to the long distances. It takes about three weeks to deliver water from Hume Dam to Sunraysia. “Shortfalls” can occur when river operators aren’t able to deliver people their water – including irrigators and the environment – where and when they want to use it.

In the River Murray downstream of the Barmah Choke, there has always been a risk of not being able to deliver all the water that people own during peak demand periods over summer and autumn. River operators have a strong track record of actively managing the system to deliver water when and where it is wanted and avoid such shortfalls. However, a shortfall can happen, if there is either:

  • a heatwave and a sudden spike in demand (a delivery shortfall), or
  • not enough capacity in the system to supply water to meet all downstream needs throughout summer and autumn (a system shortfall).

Understanding and managing delivery risks together

Victoria is working with the other River Murray states, New South Wales and South Australia, along with the Murray-Darling Basin Authority to better understand delivery risks, including how the risks are changing and how we can collectively manage them. The Independent Panel overseeing this interstate delivery risks work has reported that delivery risks are real, and that they will increase in the future.

A joint report, Managing Delivery Risks in the River Murray System, was published in November 2020 that presents key findings from recent studies about these risks and the actions needed to support governments and water users to manage them.

The Department of Environment Land Water and Planning has prepared a fact sheet that summarises the key elements of this report to help water users and communities better understand delivery risks in the River Murray System, what’s changing and the actions needed to help governments and water users respond to these risks.

Victoria is working with the other River Murray governments to make sure water users are better informed about their delivery risks, including the latest information about risks in this report, so they can consider these in managing their business risks.

What’s changing in the system

There have been significant changes across the southern connected Murray-Darling Basin over the last 10-20 years. Changes in both demand (more water being delivered to the Murray downstream of Barmah) and supply (reduced capacity) have increased the challenge of delivering water to River Murray users where and when it is needed without damaging the environmental health of our waterways.

Climate change will further decrease supply due to less rainfall and increase demand due to warmer weather – this is expected to further exacerbate delivery risks in the Murray downstream of Barmah.

A high-level summary of the changes is presented in the figure below.

DeliveryRisks Murray-DarlingBasin

More information

More information on these changes can be found in a series of reports prepared and commissioned jointly by the Murray-Darling Basin Authority (MDBA), Victoria, New South Wales and South Australia to better understand and manage delivery risks. These include:

As more information becomes available it will be published on the MDBA’s water demand (shortfalls) website

What is the risk of River Murray shortfall this season? 

During the peak irrigation season the MBDA reports on the current risk of a delivery shortfall in the River Operations Weekly Report.

The Annual Operating Outlook for the River Murray System usually includes commentary on the risk of system shortfall each year. This outlook is published by the in July and updated in December.

What does this mean for you?

Water users in the Murray downstream of Barmah Choke need to be aware that delivery risks are real and that while river operators will do everything they can to avoid shortfalls, there may be occasions where that can’t be done and their water use needs to be rationed. 

When shortfalls in the River Murray system cannot be avoided, deliveries to water users in the affected reach, including in NSW and South Australia, will need to be rationed to share the burden of the shortfall. In Victoria, temporary rationing will be applied to: 

  • Private diverters in proportion to their extraction share, or
  • Irrigation district customers in proportion to their delivery share.

The need to restrict water users has been very rare. River operators have been able to use the system’s buffering capacity to avoid the need for rationing of deliveries to Murray water users on all but two occasions. In March 2002, a 10 gigalitre shortfall affected all water users over a two-week period. Environmental water holders were also restricted on one occasion in late 2018 when channel capacity was fully committed to running the system to meet expected summer demands for both irrigation and environmental use.

To manage the impacts of a shortfall to their irrigation business, water users may choose to build on farm storage or talk to their water corporation about accessing additional delivery share or extraction share.